From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A2B833D6C7 for ; Tue, 24 Mar 2026 22:54:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774392844; cv=none; b=HdjRLajH4ItSlPlt7wTUZLsDSFSL9lTIA6h2Tm4QJB4F7bXQVPHN6h6M1GVwuFSkrxdukGeDCWqoE+FTce6Nmt5Hy0EVYiR4NINzbQzVjURQtR3JzpNdZmlJnx/4cfif4g8uauVuTQH3YesWwpAE5yzyFS82WejyYSbNOnvVtbc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774392844; c=relaxed/simple; bh=ZyuZ9qoGqgdh9poTQRYTQAip35PttZSzvL7YWxUZhpE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XO055mFL0UqLcRAJlU9J4nX25RWzZGnx9YjDokGmjoYA9/Kjmmh5gnvSLosP2K/vPF3EoruIvrr7HaVyje56+Xa4kUBMZGcByDB5tARvtisRu/Na+MpKq1v9ejZnCB28WzaEggh9DOO8N4Cmf4NbncFCCr+EN40JUwPd1YYjNKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=sYrRafxV; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="sYrRafxV" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=QxAjp1qOIQ/krE7SDbSIFLiiWtI9H9h0ogzjwCrC7VE=; b=sYrRafxVZRZJCx8MjR6c3tFoVN E/imbQBgzAxnfbaudKWfjGSmQZNvLOksSofE+VJxZsKeqGd68OjCLp9uJsC5qv0ZKi2jApbnnW/0s 20OLoMDW4QTXG9lqdgMOXNsH7q+Ri+0zD2WsFlyMN4Hk6ZdVIGrxXVo0rjL8EgNi7NU2jo6++hBKI Nh/Nb8wU7xHoqRVLIDZn4flj7HjeDWX8qIFDFv+/59UJ26/qw6h7ibOYJvgrGTxSv/mqgtFX3MvLU z9X6KMlXsjjZlpjBH21iXzfOg2HaMlWUpMetjAD1VN1hUSrn8vXhYlVyxDSNplikNAR0yvMV0oYVg ti7waniA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:45718) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1w5AdL-000000002g0-0xgk; Tue, 24 Mar 2026 22:53:59 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1w5AdJ-000000005Sf-0xu7; Tue, 24 Mar 2026 22:53:57 +0000 Date: Tue, 24 Mar 2026 22:53:57 +0000 From: "Russell King (Oracle)" To: Daniel Wagner Cc: Andrew Lunn , netdev@vger.kernel.org, Florian Fainelli , Heiner Kallweit , bcm-kernel-feedback-list@broadcom.com Subject: Re: [PATCH net-next] net: phy: bcm84881: add BCM84891/BCM84892 support Message-ID: References: <20260324152503.1522071-2-wagner.daniel.t@gmail.com> <5ff11a7f-6f92-4488-8138-9f8d6210ae30@lunn.ch> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Russell King (Oracle) On Tue, Mar 24, 2026 at 09:59:02PM +0000, Daniel Wagner wrote: > > Can you confirm whether bit 0 changes depending whether the PHY has > > link. I don't know whether that's media link or host-side link, so > > I suggest checking both. > > Bit 12 does seem to track copper link state in my test: > [0s] 0x3107 bit12=1 carrier=1 plugged > [4s] 0x2107 bit12=0 carrier=0 unplugged > [19s] 0x3107 bit12=1 carrier=0 replugged, PHY sees it > [20s] 0x3107 bit12=1 carrier=1 phylib poll catches up > > Bit 0 stayed at 1 through all of that, and through ifdown/ifup too. > I'm not sure what it is, but it doesn't appear to track either link > under the conditions I can test. > > Bits[4:1] stayed at 3 through all of it: copper transitions, different > copper speeds (1G, 2.5G), ifdown/ifup, on both BCM84891 and BCM84892. > No USXGMII codes. I suggest this is not the same register bit allocation as on the bcm84881 in that case. Also note that phylib's poll "catches up" because the link bit in BMSR is intentionally sticky-down to ensure that link-down events are not missed - if the link was down and then comes up, it intentionally takes two reads to indicate link up to ensure that the link down state doesn't get lost. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!